1. Field of the Invention
The present invention relates to a sleeve connector for an electromagnetic clutch coupled with a vehicle compressor, and more particularly, to a sleeve connector which is an electric power connection part of an electromagnetic clutch field coil assembly in an air conditioner for a vehicle, wherein one end of the sleeve connector for the electromagnetic clutch is connected to a connection port formed at the electromagnetic clutch field coil assembly and a power terminal is inserted into the other end.
2. Description of the Related Art
In general, a vehicle compressor for an air conditioner is operated by means of a driving power of an engine, and an electromagnetic clutch are mounted together so as to intermittently operate the vehicle compressor only in a case where air conditioning is required.
FIG. 1 is a cross-sectional view of an electromagnetic clutch of a compressor.
An operation principle of the compressor 220 will be briefly described below with reference to FIG. 1. First, in a case where an engine is operating, a pulley 260 connected from a driving shaft of the engine (not shown) through a belt (not shown) rotates. Further, the pulley 260 is connected to a rotating shaft of the compressor 220 via the electromagnetic clutch. In general, a rotor 280 is coupled with the pulley 260, and an electromagnetic clutch field coil assembly 210 having a coil 211 and a coil housing 212 is disposed with the rotor 280 at a minute interval.
Furthermore, the rotor 280 is connected to the rotating shaft of the compressor 220 with a bearing 270 interposed therebetween.
If a driver turns on a switch for an air conditioner in this state, a disc 221 fixedly coupled with the rotating shaft of the compressor 220 and a disc 261 fixedly coupled with the pulley 260 are contacted with each other to rotate together by means of a frictional force while electric power is applied to the electromagnetic clutch field coil assembly 210, so that the compressor 220 is operated.
On the contrary, unless electric power is applied to the electromagnetic clutch field coil assembly 210 through electric power connection lines 230 and 240, since the disc 261 of the pulley 260 and the disc 221 of the compressor 220 are separated from each other, the power is cut off and the compressor 220 does not operate.
Electric power may be applied to the electromagnetic clutch field coil assembly 210 by manually controlling the switch of the air conditioner, and the application of the electric power to the electromagnetic clutch field coil assembly 210 may be automatically controlled depending on a room temperature of a vehicle by connecting it to an electronic control unit (ECU) that is not shown.
Meanwhile, in the operation process of the compressor, counter electromotive force that is reversely transferred from the electromagnetic clutch to the power supplying part may be generated. Since there is a property that a magnetic field induced along a current flow induces again an electric field according to a change in the magnetic field, in order to remove the induced magnetic field and the induced electromotive force because of characteristic of the electromagnetic clutch which has to secure a sensitivity to command following, a resistor and a diode are provided in the electromagnetic clutch field coil assembly. However, if the resistor and diode are provided in the electromagnetic clutch field coil assembly, it is apprehended that the parts are damaged by heat generated in the electromagnetic clutch field coil assembly. Thus, it is preferable that the resistor and diode are provided at an outside of the electromagnetic clutch field coil assembly.
FIG. 2 is an exploded perspective view of a conventional coupling relationship between a sleeve connector 200 for an electromagnetic clutch and an electromagnetic clutch field coil assembly 300. The sleeve connector 200 has terminals 150 and 160 for coupling with a power supplying line and the electromagnetic clutch field coil assembly 300. The terminals 150 and 160 are made of a conductive metal and a pair of terminals is provided in the sleeve connector 200. The pair of terminals 150 and 160 is plastic-molded to be insulated from each other and thus form a housing 180. After the terminals 150 and 160 are plastic-molded in a metal mold, the diode and resistor are installed in the housing 180 and then epoxy 170 is injected therein, thereby fabricating the sleeve connector 200. The electromagnetic clutch field coil assembly 300 is formed with a terminal insertion groove 250 in which the terminals are inserted.
In general, the diode and resistor are built into the sleeve connector or an electric power connection part of an electromagnetic clutch field coil assembly. Prior arts relevant to a built-in position or method of the diode and resistor are provided as follows.
In Japanese Patent Laid-Open Publication No. H07-127662 (published on May 16, 1995), there was disclosed a surge voltage absorbing device for absorbing a surge voltage generated when power supplied to a field coil assembly is cut off temporarily, in which a diode connected with a terminal is provided in a connector.
Further, in PCT WO 2004/067982 (published on Aug. 12, 2004) which was filed by the applicant, there was disclosed a construction in which a diode and a resistor are used for absorbing a serge voltage, and a sleeve connector is provided so as to connect between an electromagnetic clutch field coil assembly and an external power source, and the sleeve connector is coupled with a connection part formed at the electromagnetic clutch field coil assembly.
FIG. 3 is an illustration of a conventional electromagnetic clutch field coil assembly. As shown in FIG. 3, the conventional electromagnetic clutch field coil assembly is injection-molded in a status that two terminals 150 and 160 are put in a mold, and a diode 120 and a resistor 110 are properly disposed in a space, and then an upper side thereof is finished with epoxy.
However, due to the additional epoxy process, there is a problem that fabricating cost is increased and productivity thereof is reduced. And unlike in the sleeve connector for an electromagnetic clutch according to the present invention, since a holder is not used in the conventional electromagnetic clutch field coil assembly, the diode and resistor may be deviated from their original positions during the injection molding process. Further, in case that the injection molding process is performed in the state that the terminals are put in the mold, the terminals may be shorted to each other.